Precise blood lead analysis using a combined internal standard and standard addition approach with disposable screen-printed electrodes

We report here a highly accurate and efficient method for blood lead analysis (BLA) through the use of a disposable electrode. A new type of mercury-plated preanodized screen-printed carbon electrode, together with a thallium(III) internal standard, simplifies calibration and gives easily quantifiable signals for accurate BLA. A preanodization procedure improves the preconcentration ability of the working electrode through the effect of lead (Pb) complexing with an electrogenerated surface functional group, mainly >CO. Under optimized conditions, the ratio of the anodic stripping peak currents of Pb and Tl (i.e., iPb/iTl) is linear against [Pb] in the window of 1-300 ppb with a correlation coefficient and detection limit (signal-to-noise ratio = 3) of 0.999 and 0.23 ppb, respectively. This approach was used to analyze blood samples (n = 55) from workers at a local battery factory. The results are consistent with those obtained from graphite furnace atomic absorption spectroscopy and confirm the applicability of the proposed method.